Scotland Yard has received more than 300 calls and 60 reported sightings, including a member of the public who came forward saying they saw Tia leaving her grandmother's house at about noon last Friday.

Officers have collected more than 800 hours of CCTV footage from buses and trams.

Police Olympics resources have been redirected to the search, which involves around 40 detectives and 40 specialist search officers.

Investigators have focused their attention on the area around Mrs Sharp's house, with officers searching woodland and scouring rubbish bins on the south-east London estate.

They have also taken evidence from the family home and plan to hand out leaflets on trams and buses today.

Scotland Yard has been liaising with forces which have dealt with other missing person cases, including detectives in West Yorkshire who investigated the disappearance of Shannon Matthews.

A Scotland Yard spokesman said: "As is routine, we liaise with all forces that have dealt with similar cases.

"This case, like the Shannon Matthews case, involved the search for a missing child.

"This is a missing persons inquiry and we are putting all of our resources into finding her."

Mr Hazell, thought to be one of the last people to see Tia, was questioned by police as a witness for more than two hours on Wednesday before returning home.

He said the schoolgirl is "a happy-go-lucky golden angel" who has no problems at all.